{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-90189 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-90189 is an use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-90189 and fix it if it is affected.\n\nWhat it is: CVE-2026-90189 is an use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-90189 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-90189/ (Markdown: https://insights.sbomify.com/CVE-2026-90189/index.md)","id":"CVE-2026-90189","markdown":"https://insights.sbomify.com/CVE-2026-90189/index.md","name":"CVE-2026-90189","record":{"aliases":["AZL-102141","BELL-CVE-2026-90189","DEBIAN-CVE-2026-90189","GHSA-p7q5-vj3m-rc98","UBUNTU-CVE-2026-90189"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel null_blk module allows local attackers to trigger a use-after-free, potentially leading to privilege escalation or code execution.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: register configfs subsystem after creating default devices\n\nIn null_init(), configfs_register_subsystem() currently runs before\nregister_blkdev(), so when null_blk is built as a module, a racing mkdir()\n+ poweron from userspace can reach null_add_dev() while null_major is still\n0. __add_disk() then hits WARN_ON(disk-\u003eminors) (major=0 with minors!=0)\nand fails:\n\n[root@fedora ~]# [ 2366.521436] WARNING: block/genhd.c:476 at __add_disk+0x8a7/0xde0,\n[ 2366.523552] Modules linked in: null_blk(+) nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib\n[ 2366.529081] CPU: 26 UID: 0 PID: 1600 Comm: sh Not tainted 7.2.0-rc1+ #66 PREEMPT(full)\n......\n[ 2366.547251] Call Trace:\n[ 2366.547575]  \u003cTASK\u003e\n[ 2366.547831]  ? _raw_spin_lock+0x84/0xe0\n[ 2366.548260]  add_disk_fwnode+0x114/0x560\n[ 2366.548739]  null_add_dev+0x102d/0x1b80 [null_blk]\n[ 2366.549310]  ? __pfx_null_add_dev+0x10/0x10 [null_blk]\n[ 2366.549906]  ? mutex_lock+0xde/0x1c0\n[ 2366.550361]  ? __pfx_mutex_lock+0x10/0x10\n[ 2366.550827]  nullb_device_power_store+0x1e7/0x280 [null_blk]\n[ 2366.551499]  ? __pfx_nullb_device_power_store+0x10/0x10 [null_blk]\n[ 2366.552177]  ? __kmalloc_cache_noprof+0x1f5/0x470\n[ 2366.552748]  ? configfs_write_iter+0x35c/0x4e0\n[ 2366.553242]  configfs_write_iter+0x286/0x4e0\n[ 2366.553787]  vfs_write+0x52d/0xd00\n[ 2366.554169]  ? __pfx_vfs_write+0x10/0x10\n[ 2366.554679]  ? __pfx___css_rstat_updated+0x10/0x10\n[ 2366.555196]  ? fdget_pos+0x1cf/0x4c0\n[ 2366.555649]  ksys_write+0xfc/0x1d0\n......\n\nAdditionally, the err_dev path destroys all devices on nullb_list while\nconfigfs is still registered. If a racing mkdir() + poweron puts a user\ndevice on the list, null_destroy_dev()-\u003enull_free_dev() kfrees the user\ndevice's nullb_device but /sys/kernel/config/nullb/\u003cname\u003e is still\nreachable. Any userspace access to the item will trigger a UAF.\n\nFor simplicity, move configfs_register_subsystem() to the end to solve\nthe problems above.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"null_blk: register configfs subsystem after creating default devices","id":"CVE-2026-90189","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"use_after_free","year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"null_blk: use DEFINE_MUTEX for the file-scope mutex","id":"CVE-2026-90190"},"packages":[],"prev":{"headline":"null_blk: free global tag_set on init error path","id":"CVE-2026-90188"},"products":["Linux"],"published":"2026-09-17","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in the Linux kernel null_blk module allows local attackers to trigger a use-after-free, potentially leading to privilege escalation or code execution.","url":"https://insights.sbomify.com/CVE-2026-90189/"}